1. Field of the Invention
The present invention relates to an electronic component and a method of manufacturing such electronic component, and more specifically to an electronic component having an outer sheath structure that protects components and circuits installed on a substrate and providing electrical functions, as well as a method of manufacturing such electronic component.
2. Description of the Related Art
Electronic components having a resin outer sheath (or resin sealing) structure that protects, by means of covering with a resin material, components and circuits installed on a substrate or board and providing electrical functions, have traditionally been known. Incidentally, electronic components installed in mobile phones and other portable electronic devices face a strong demand for high durability against changes in the use environment (temperature, humidity, etc.) from the viewpoint of reliability.
Examples of such electronic components include the surface-mounted wire wound inductor described in Patent Literature 1, which comprises a drum-shaped ferrite core and a conductive wire winding around the ferrite core, with the conductive wire covered and protected with an outer sheath resin material. Here, Patent Literature 1 discloses that, by adjusting the composition of the outer sheath resin material, the linear expansion coefficient of the ferrite core can be brought closer to that of the outer sheath resin and therefore the durability of the inductor against changes in temperature can be enhanced. Such an inductor applying a ferrite core is suitable for high-density mounting and low-height mounting on a circuit board because it is generally possible to reduce the outer dimensions (especially height dimension) of such an inductor.